At the present time beds and chairs which are adjustable are known. Thus, it is known to provide hospital beds including a mattress support which may be raised or lowered at either end to afford a longitudinal adjustment of the mattress as an entirety. However, so far as the present applicant is aware it is not known to provide hospital beds which include mattresses the level of which may be adjusted transversely as well as longitudinally.
It is also believed that the art is singularly lacking in a mattress support comprising three longitudinal sections which are hingedly connected along transverse axes together with power means for adjusting either end section with respect to the middle section. Such an arrangement is believed to be particularly desirable in a hospital bed because in many instances a section of the bed may be adjusted to avoid the use of traction. Also, while it is known to provide a hospital bed with a space or recess to accommodate a bed-pan, the placement and removal of a bed-pan requires the services of an attendant, such as a nurse or porter. And finally, so far as hospital beds are concerned, it is not the practice to provide a mattress in the form of a plurality of inflatable bags into which air under pressure may be introduced selectively or exhausted from any bag. Such an arrangement is extremely desirable from the aspect of the comfort of the occupant of the bed.
It is known to provide a bed including a mattress comprising a plurality of inflatable bags for a single occupant, or for double occupancy but the known arrangements for double occupancy do not suit the comfort of two occupants when their size, contour, and personal dispositions are considered. This is particularly true when the mattress includes a head section which is adjustable and common to both occupants.
Adjustable chairs and particularly those of incompacitated or handicapped persons have much in common with a hospital bed and this particularly true in accordance with the present invention. It is known to provide an adjustable chair including a supporting frame and a body supporting assembly comprising three sections which are hingedly connected. These are a back support, a middle support on which the thigh portion of the occupant rests, and a leg support. Power means have been provided for swinging the back and middle supports as a rigid unit upwardly with an occupant thereon to facilitate removing his person from the chair.
Due to the weight of the average occupant this power means has taken the form of a screw stem and an electric motor. Similar power means have been provided for swinging the leg support relative to the middle support. It has been found from practical experience that such screw stems are unsatisfactory particularly when the back and middle supports are swung upwardly as a unit with an occupant thereon because of the large thrust required. If the screw stems are of a plastic it is literally impossible to provide a practically operable device of this character. The present invention proposes the use of bellows like inflatable bags to cause the swinging movements of the body supporting assembly.
It is of course known to provide chairs the back and seat of which are covered by inflatable bags, however, it is not known to provide a chair which includes both the inflatable bags which cover the seat and back and also the bellows like bags which cause the swinging movements between the body supporting assembly with a single air compressor together with a conduit system and control valve whereby air under pressure may be selectively introduced into any of the bags and exhausted therefrom.